Spring closing system for circuit breakers



May 17, 1960 R. v. STARR SPRING CLOSING SYSTEM FOR CIRCUIT BREAKERS Filed Nov. 12, ess

3 Sheets-Sheer. 1

TNVENTOR. Inez-e7- lt 5mm? BY W May 17, 1960 R. v. STARR SPRING CLOSING SYSTEM FOR CIRCUIT BREAKERS Filed Nov. 12, 1958 5 Sheets-Sheet 2 INVENTOR. lPOA SZT 14.974168 BY W May 17, 1960 R. v. STARR SPRING CLOSING SYSTEM FOR CIRCUIT BREAKERS 3 Sheets-She et 3 Filed Nov. 12, 1958 INVENTOR. $455,27- 1/. 57am? United States Patent SPRING CLOSING SYSTEM FOR CIRCUIT BREAKERS Robert V. Starr, E. Pikeland Township, Chester County,

Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application November '12, 1958, Serial No. 773,332 14 Claims. (Cl. 200-169) My invention relates to a stored energy closing system for circuit breakers and more particularly relates to a manually operated spring closing system.

A primary object of my invention is to provide a novel and highly reliable manually operated spring closing system. 7

Another object of my invention is to provide a novel spring closing system for circuit breakers which are manually operated and provides a closely controlled closing energy for closing and latching a circuit breaker against overloaded currents.

A further object of my invention is to provide a novel spring closing mechanism which can close and latch the circuit breaker contacts closed against the rated shorttime delay tripping current of the breaker.

Another object of my invention is to provide a novel spring closing mechanism for circuit breakers which gives a uniform high closing speed forall operating conditions.

A still further object of my invention is to provide a novel manually operable spring closing mechanism in which the circuit breaker contacts cannot be teased and in which the operator loses control of the closing cycle once the contacts begin to close.

These and other objects of my invention will become apparent from the following description taken in conjunc- ,tion Withthe drawings, in which Figure 1 shows a side view of the operating mechanism :of my novel invention with the operating mechanism in its inactive position.

Figure 2 is similar to Figure 1 and shows the operat-.

:ing mechanismimm'ediately after the closing operation is :started. V

Figure 3 is similar to Figures 1 and 2 and showsthe state by means of a trip latch of the circuit breaker. When the collapsible mechanism is in its uncollapsed state, or force transmitting state, the force transmitted from the spring is taken through the first stage closing cam and the second stage closing cam at the output of the collapsible mechanism. Accordingly it is possible to achieve a substantial degree of force amplification and a designer has a substantial flexibility in matching the forcedisplacement curve of the closing springs to the forcedisplacement curve of the springs which normally maintain the circuit breaker movable contact in its disengaged position.

A further feature of the invention as will become apparent hereinafter is that the closing springs are normally in an uncharging condition. These springs are charged only during a first portion of the manual closing cycle and are thereafter'discharged when transferring their energy to the movable contact.

' After the closing operation, the main closing spring becomes confined to a fixed shaft whereby its force transmitting ability is limited and a relatively light spring may reset the mechanism.

16 are pivotally supported at pivots 15 and 17 respectively i and their upper portions are pivotally connected to links position of the operating mechanism immediately after the conditions of a manual closing stroke when the mechanism is already tripped or where the circuit breaker is tripping immediately after the closing operation.

Figure 5 is an exploded perspective view of the mechanism of the Figures 1, 2 and 3.

In my novel operating mechanism, I provide an operating handle which is operatively connected to a charging cam. The charging cam carries a trip pin which automatically initiates the closing operation when the charging cam has charged the spring to some predetermined value. Thus the charging spring is connected to' a first stage closing cam which is latched by a hold up latch means which normally defeats the operation of the first stage closing cam. When the charging cam reaches the above noted predetermined position it will unlatch the hold up latch and first stage closing cam becomes operable.

The first stage closing cam is connected to the movable contact of the circuit breaker through a collapsible mechanism which has a second stage close cam at its output.

" This collapsible mechanism is held in its force transmitting 18 and 20 respectively which are pivotally mounted at their opposite end to operating arms 22 and 24. The operating arms 22 and 24 are mounted on a common jack shaft 26, which jack shaft would support other operating arms of other poles not shown in Figure 5.

Accordingly, each of the movable contacts of the circuit breakers will move as a unit by virtue of the common jack shaft 26.

Movable contacts 14 and 16 are normally biased to a disengaged position by a main opening spring 28 of the circuit breaker. The essence of the instant invention is to provide an operating means for applying energy to the jack shaft 26 and close the movable contacts of the breaker such as contacts 14 and 16 against the force of spring 28. The circuit breaker contacts of the front pole of Figure 5 are schematically illustrated in Figures 1 through-4 by dot-dash lines and the closed and opened position of the contacts are similarly illustrated. My novel operating mechanism is shown in each of Figures 1 through 5 and includes a closing handle 30 which is pivotally mounted on a fixed pivot 32. Manual operating handle 30 carries a charging roller 34 which is pivotally carried by pin 36 which is mounted on the operating handle 30. The operating handle 30 and its charging roller 34 cooperate with a charging cam 38 which is pivotally mounted on a fixed pivot 40. Charging cam 38 pivotally mounts a lower closing pin 42 and cooperates with a closing trip pin 44 which is mounted on charging cam 30. Closing pin 42 is then positioned within a slot 46 of spring link 48 and is pivotally connected to the lower spring carrier 50 (Figures 1 and 5). Spring link 48 has an aperture 52 at the upper end thereof as seen in Figure 5 and the aperture carries a pin 54 which, in addition to other elements, supports the upper spring carrier spring 56 as best seen in Figure 5.

The main closing spring 58 (Figures 1 and 5) is carried between the upper spring carrier 56 and the lower spring carrier 50 as is best seen in Figure 5 and the spring link 48 is adjacent to spring 58. If desired, two spring links 48 and two springs 58 may be used, spaced equally on either side of the center of the mechanism with the springs outside. Figure shows a single spring 58 exploded away from its link 48 to simplify the drawing. Pin-54 which is the upper spring pin, further carries a closing stroke stop bushing 60 which cooperates, as will be seen more fully hereinafter, with the stopping member 62 of Figures 2 and 3 as well as the first stage closing cam 64; Thus, stop bushing 60 and first stage closing cam 64 are provided with openings 66 and 68 respectively (Figure 5) which accepts upper spring pin 54. The first stage closing cam 68 is pivotally mounted at a stationary pivot point 70 which also pivotally mounts the prop latch 72 of the circuit breaker. Prop latch 72 is biased to rotatein a clockwise direction about its pivot 70' by means of biasing spring 74, its clockwise rotation being limited by stop 76 which abuts the leg 78 of prop latch 72.

In order to allow the spring to be charged during the initial part of the closing cycle, a hold up latch 80 is pivotally mounted at pivot point 82 and it is biased in a counter-clockwise direction by biasing spring 84 against the stop 76. Surface 86 of hold up latch 80 cooperates with pin 44 of charging cam 38 in order to allow the energy of spring 58 to be transmitted to thecontact mechanism.

The cam surface of closing cam 64 cooperates with the roller 88 of roller carrier 90 which pivotally carries roller 88. Carrier 90 forms the collapsible mechanism which connects closing cam 64 to the contact mechanism and pivotally carries a main latch roller 92 and output roller 90.

Roller carrier 90 is carried by the roller carrier support member 96 which is pivotally supported from a fixed pivot 98. The right hand end of the carrier support member 96, a portion of the carrier 90 and the main latch roller 92, are pivotally connected by a common pin seen as pin 100 in Figure 5.

The roller 92 is normally held in the position shown by means of the main latch 102 whichis pivotally mounted at a fixed pivot point 104. In this position, collapsible member 90 is capable of force transmission. The main latch 102 is biased to rotate in a counterclockwise direction under the influence of biasing spring 106 and the extent of its counter-clockwise rotation is limited by stop pin 108. The clockwise rotation of member 102' is limited in extent by stop means 110. Main latch 102 is terminated at its left hand end by a pivotally mounted roller 112 which is normally engaged by pivotally mounted latch member 114 which may be the trip latch of the circuit breaker system and is operable either by the trip bar 116 (Figures 1 through 4) or by the latch bar 118 (Figures 1 through 4).

It is now possible to describe the operation of my novel manually operated spring closing mechanism. It will be first assumed that the circuit breaker contacts are open and the spring closing mechanism is in its inactive position as seen in Figure 1. In order to close the circuit breaker, the operator moves the manual operating handle 30 downward as shown in going from Figure 1 to Figure 2. Figure 2 shows the operating mechanism after the handle has been partially rotated in a clockwise direction out of its pivot 32. As shown, this motion moves roller 34 engaged with the undersurface of charging cam 38 so that charging cam 38 rotates in a counter-clockwise direction about its pivot 40. This motion will pull the lower spring pin 42 downwardly, thus bringing the first stage closing cam which is attached to the lower spring pin 42 through the spring 58 in a counter-clockwise direction and into engagement with the upper surface of roller 88. This will then causecarrier 90 to be rotated counter-clockwise about roller 92 until the lower right hand surface of roller 88 engages the upper left hand surfaceof the hold up latch. 80. It is to be noted that the roller 90 will not be forced to the left under the camming actionof hold up latch 80 since the main latch 102 and the roller carrier support 96 define a rigid support for carrier 90 when the main latch 102 is in position. During this operation the upper spring pin 54 has moved downwardly to a slight extent until all of the mechanism play has been taken up. Once, however, the connection between the driving cam 64 and roller 88 becomes rigid the upper spring pin 54 can go no further so that continued downward movement of operating handle 30 and lower spring pin 42 will elongate and charge spring 58. The specific position shown in Figure 2 illustrates the beginning of this charging action. This charging will continue until the lower end of spring 58 reaches its fully charged position.

At this time the closing trip-in pin 44 on charging cam 38 has moved to the position of Figure 3 and it engages the cam surface 86 of hold up latch 80 so as to rotate latch 80 in clockwise direction about pivot point 82 against the force of the biasing, spring 84. Thisbrings the upper left hand surface of hold latch 80 out of the path of roller 88 so that the roller 88 may be forcefully driven downward by the closing cam 64 under the influence of charging spring 58. Spring link 48 will move downwardly with the slot 46 with closing cam 64 since the upper spring pin 54 carries charging cam 64 and the opening link 48. As the roller 88 is driven downwardly, the roller carrier 90 is rotated in a clockwise direction about the pivot of roller 92 which is held fixed when main latch 102 is in its latched position. Accordingly, roller 94 at the left hand end of carrier 90 acts as a second stage cam and picks up the undercam surface 130 of contact operating arm 24, thus driving contact arm 24 and jack shaft 26 in a counter-clockwise direction to close the circuit breaker contacts. Once the downward stroke of the various elements reach their limiting position, the bufier bushing 60 will engage the cooperating stop 62 as shown in Figure 3.

It will be noted that this two stage cam operation gives considerable force amplification and lends flexibility in the design of the system so that the force-displacement characteristic of spring 58 may be matched to the forcedisplacement characteristic to the contact opening spring 28 of Figure 5.

In order to hold the circuit breaker contacts in their engaged position, the circuit breaker prop latch 72 is cammed out of the path of roller 88 against the force of biasing spring 74 as it moves downwardly. Once the roller 88 is below the prop latch, spring 74 immediately causes the prop latch 72 to return to its initial position as shown in Figure 3 where it blocks the return path of roller 88. Therefore, roller 94 and roller carrier 90 is held in the position of Figure 3 to keep the circuit breaker contacts closed.

After this closing operation, a relaxing of operating handle 30 allows reset spring 51 to pull the lower pin 42 upwardly, it being noted that the spring 58 is completely confined to the spring link 48 after the closing operation.

Accordingly, link 48 will move upwardly to reset the upper cam 64, the charging cam 38, and handle 30 so as to bring these members to the position shown in Figure l where the operating handle 30 comes to rest against its stop 31. A subsequent handle operation will move the above noted components through the reverse of the reset motion while the circuit breaker contacts remain closed because the roller 88 is latched and cannot be interposed between the charging cam 38 and the hold up latch to charge the closing spring 58.

Figure 4 illustrates the operation of my novel manual closing mechanism in the event that the circuit breaker is tripped during or before the time that the manual closing operation is attempted. In essence, the trip latch 114 has been removed from roller 112 of main latch 102 thus permitting a clockwise rotation of trip latch 102 against the influence of spring 106. The reaction of roller 92. 0 .1 the @CGGntric support surface-of the main 5. latch 2 produces this motion. Whenthis happens, the position of roller 92 is no longer fixed so that a force applied to roller 88 of carrier 90 by the first stage closing cam 64 will merely cause a rotation of carrier 90 with the junction between roller 94 and cam surface 130 of operating arm 24 as a pivot for this rotation. That is to say, negligible force will be transmitted between roller 94 and cam surface 130 so that the circuit breaker contacts will not be affected since the collapsible mechanism is in a collapsed condition.

This feature further imparts trip-free characteristic to the breaker. Thus, as the operator moves the handle 30 from the position of Figure 1 to the position of Figure 3 and the circuit breaker contacts close on a fault, the trip latch systemwill unlatch latch 114 so that as the contacts open, the contact carrier 90 will rotate with the roller 88 as a pivot and no force will be transmitted through the linkages through the operating handle 30. Thus, by temporarily supporting the roller 92 and by camming the latch surface of main latch 102 which engages roller 92 so that it will always be driven in a counter-clockwise direction if unlatched, I achieve all of the essential safety features necessary in this type of unit.

Although I have described preferred embodiments of my novel invention, many variations and modifications will now be obvious to those skilled in the art, and I prefer therefore to be limited not by the specific disclosure herein, but only by the appended claims.

I claim:

1. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said springwhen said spring is charged; said'charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a secondportion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected be tween said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism.

2. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said said energy transferring mechanism; said energy t'ran's' movable to a defeated position responsive to operation of spring, an operating means, a latching means for latching 7 said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second'portion of said spring in a relatively fixed position when said operating means is operated to move said firstiportion .of said spring to said charged position; said energy transferring mechanism being operatively connected between a said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said springlto said. circuit breaker movable contact through .7

said circuit breaker trip latch to prevent energy transmission from said spring to said circuit breaker movable contact.

3. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism fortransferring the energy stored in saidspring when said-spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said.

latch releasing said second portion of said spring when said defeating means is operated to permit discharge ofsaid spring and transmitting of the energy stored in said.

spring to said circuit breaker movable contact through said energy transferring mechanism; said energy transmittingmechanism being operatively connected to said second portion of said spring through a first stage cam means,-

said-energy transmitting mechanism being operatively connected to said circuit braker contact through a second of an opening biasing means associated with said circuit breaker movable contact.

4. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating'means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said energy transmitting mechanism being operatively connected to said second portion of said spring through a first stage cam means, said energy transmitting mechanism being operatively connected to said circuit breaker contact through a second stage cam means; said first and second stage cam means permitting the matching of the force-displacement curve of said chargeable spring to the force-displacement curve of an opening biasing means associatediwith said circuit breaker movable contactysaid energy transmitting mechanism including a collapsible force transmitting member; a circuit breaker trip latch; said collapsible force transmitting member being normally held in a force transmitting position by said circuit breaker trip latch when said circuit breaker trip latch is in a latched position; said force transmitting member being movable to a defeated position responsive'to operation of said circuit breaker trip latch to prevent energy transmission from said spring to said circuit breaker movable contact.

5. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable Spring, a charging mechanism for charging said springyan operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said energy transmitting mechanism including a first force transmitting cam and a second force transmitting cam; said first and second force transmitting cams permitting the matching of the force-displacement curves of said chargeable spring and the opening bias of said circuit breaker movable contact.

6. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging 1 said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said defeating means being carried by said charging mechanism and being moved into engagement with said latch means to defeat said latch means when said first portion of said spring reaches a predetermined charged position.

7. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said 8' spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said energy transmitting mechanism being operatively connected to said second portion of said spring through a first stage cam means, said energy transmitting mechanism being operatively connected to said circuit breaker contact through a second stage cam means; said first and second stage cam means permitting the matching of the force-displacement curve of said chargeable spring to the force-displacement curve of an opening biasing means associated with said circuit breaker movable contact; said defeating means being carried by said charging mechanism and being moved into engagement with said latch means to defeat said latch means when said first portion of said spring reaches a predetermined charged position.

8. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving andmaintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said energy transmitting mechanism including a collapsible force transmitting member; a circuit breaker trip latch; said collapsible force transmitting member being normally held in a force transmitting position by said circuit breaker trip latch when said circuit breaker trip latch is in a latched position; said force transmitting member being movable to a defeated position responsive to operation of said circuit breaker trip latch to prevent energy transmission from said spring to said circuit breaker movable contact; a prop latch means; at least a portion of said collapsible force transmitting mechanism being moved to a predetermined position when said circuit breaker movable contact is moved to a closed position; said portion of said energy transmitting mechanism being latched by said prop latch means to maintain said circuit breaker movable contact closed when operated by said closing mechanism.

9. A spring charging mechanism; said spring charging mechanism including a spring, a latching means, an operating means, and a latch defeating means; said spring having a first portion operatively connectible to a load and a second portion operatively connectible to said operating means; said latch means being positioned to latch said first portion of said spring in a predetermined position and being movable to a latch defeated position; said operating means being operable to move and maintain 9 7 said second portion of said spring to a predetermined charged position; said latch defeating means being carried by said operating means; said latch defeating means being brought into engagement with said latch when said second portion of said spring reaches and is maintained in said charged position.

10. A spring charging mechanism; said spring charging mechanism including a spring, a latching means, an operating means, and a latch defeating means; said spring having a first portion operatively connectible to -a load and a second portion operatively connectible to said operating means; said latch means being positioned to latch said first portion of said spring in a predetermined position and being movable to a latch defeated position; said operating means being operable to move and maintain said second portion of said spring to a predetermined charged position; said latch defeating means being carried by said operating means; said latch defeating means being brought into engagement with said latch when said second portion of said spring reaches and is maintained in said charged position; said operating means comprising a manually operable operating lever; a continuous motion of said operating lever charging said spring and then discharging said spring when a predetermined charged position is reached.

11. An energy transmitting mechanism for connecting a driving means to a driven means; said driven means having biasing means associated therewith for resisting motion thereof; said energy transmitting mechanism being operatively connected to said driving means by a first cam mechanism and being operatively connected to said driven means by a second cam mechanism; said first and second cam mechanisms permitting the matching of the force-displacement characteristics of said driving means and said driven means.

12. An energy transmitting mechanism for connecting a driving means to a driven means; said driven means having biasing means associated therewith for resisting motion thereof; said energy transmitting mechanism being operatively connected to said driving means by a first cam mechanism and being operatively connected to said driven means by a second cam mechanism; said first and second cam mechanisms permitting the matching of the force-displacement characteristics of said driving means and said driven means; said driving means being a chargeable spring.

13. An energy transmitting mechanism for connecting a driving means to a driven means; said driven means having biasing means associated therewith for resisting motion thereof; said energy transmitting mechanism be ing operatively connected to said driving means by a first cam mechanism and being operatively connected to said driven means by a second cam mechanism; said first and second cam mechanisms permitting the matching of the force-displacement characteristics of said driving means and said driven means; a collapsible force transmitting means; said first and second cam mechanisms being operatively connected to one another by said collapsible force transmitting means; a defeatable support means; said collapsible force transmitting means being normally supported by said defeatable support means.

14. A spring close mechanism for a circuit breaker movable contact; said spring close mechanism including a chargeable spring, a charging mechanism for charging said spring, an operating means, a latching means for latching said spring in a charged position and an energy transferring mechanism for transferring the energy stored in said spring when said spring is charged; said charging mechanism operatively connecting a first portion of said spring to said operating means; motion of said operating means moving and maintaining said first portion of said spring in a charged position; said latching means being movable to a latching position for latching a second portion of said spring in a relatively fixed position when said operating means is operated to move said first portion of said spring to said charged position; said energy transferring mechanism being operatively connected between said second portion of said spring and said circuit breaker-movable contact; and defeating means for said latch; said latch releasing said second portion of said spring when said defeating means is operated to permit discharge of said spring and transmitting of the energy stored in said spring to said circuit breaker movable contact through said energy transferring mechanism; said operating means being a manually operable lever; said defeating means being carried by said manually operable lever and being moved into engagement with said latch means to defeat said latch means when said first portion of said spring reaches a predetermined charged position.

References Cited in the file of this patent UNITED STATES PATENTS 2,644,053 Lingal et a1. June 30, 1953 

